Friction hinges are used for mounting lids onto laptop computers and for other devices having lid mounted displays that require accurate position control for satisfactory viewing. In such devices, it is often desirable that the lid lift slightly upon releasing of the latch that is used to keep the lid closed when the device is to be moved. This feature, or capability has become known to those in the laptop computer industry as a xe2x80x9cpop-upxe2x80x9d action. Pop-up action has been accomplished in some prior art devices by the inclusion of cam mechanisms or spring detent mechanisms. But the addition of any hardware into a laptop is undesirable because of the stringent constraints on size, weight and cost.
Our invention achieves the pop-up action by the innovative modification of hardware elements that are already present in devices having rotatable displays that require accurate positioning for good viewing. Friction hinges are ordinarily used both to attach the display to the base and to maintain the position of the display during use. Our invention uses the same springs both to produce the friction and the force needed for the pop-up action. An additional benefit of our invention is that, as the pop-up action takes place, the frictional torque is greatly reduced, thereby facilitating the pop-up motion.
Quite commonly, designers and manufacturers of devices having displays wish to provide a stop mechanism within the friction hinges. Our invention provides such a stop by means of a pin or protrusion as is well known in the prior art. Our innovation is to use this configuration in a novel manner to also provide the desirable pop-up action without any additional parts.
In the preferred embodiments, a friction hinge made with a question-mark-shaped band wrapped about a cylindrical shaft has a stop pin or other protrusion fixedly mounted to the cylindrical shaft and perpendicular to its axis. Slightly before the display reaches the fully closed position, the pin or protrusion contacts the end of the cylindrical portion of the band. The further motion traversed in fully closing the lid presses the pin or protrusion against the band causing the band to spring open a small amount and to be held there by the latch mechanism or other means provided to keep the lid fully closed. When next the latch is released to open the lid, the spring force of the band pushing against the pin or protrusion causes the lid to pop up enough to permit the user easily to grasp the lid and position it for use.
It is an objective of our invention to provide a friction hinge for mounting of displays to laptop computers and other devices which also provides a pop-up action upon releasing of a latch mechanism.
It is a further objective of our invention to provide such a friction hinge with pop-up action which can be manufactured and sold at no additional cost as compared with the cost of prior art frictional hinges containing a stop pin.
The inventive pop-up friction hinge accordingly comprises the features of construction, combination of elements, and arrangement of parts which will be exemplified in the constructions described hereinafter, and the scope of the invention will be indicated in the claims.